SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff3bb8d8732f921f34040799254f1bd27ecedb54055c28bfb95c07392a266cfb' 
  AND token = 'tyNX6gXO5BYiM4tdTLUlImIgkE7sHzIluIk3FhVz8vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}